Oil-well underreamer



T; J. MCGORMICK.' OIL WELL UNDERREAMER. APPLICATION FILED JULY 9} I920.

'%7SHEETSSHEET I.

I f I 22 INVENTOR ATTORNEY Patnted E60. 27, 1921.

T. J McCORIVHCKI OHJWELL UNDERREAMER.

APPLICATION FILED JULY9,1920

Patented Deb. .27., 1921,

2 SHEETS-SHEET 2'.

WITNESSES ATTORNEY elevation, showing v were memes J. mocomaron, or name, Havana.

OIL-WELL UND' inclines.

To all whom it may concern."

Be it known that I, THOMAS J. MCCOR- MICK, a citizen of the United States, residing at Elko, in the county of Elko and State. of

Nevada, have invented new and useful Im provements in Oil-Well Underreamers, of whlch the following is a specification.

My present invention has for its object the provision of an underreamer that is possessed of an elastic quality calculated to avert dogging of the 'aws'incident to operation, and one that is c aracterized by other features of practical advantage.

To the attainment of the foregoing the.

invention consists in the improvement as hereinafter described and definitely claimed. In the accompanying drawings, hereby made a part hereof Figure 1 is a side elevation of an underreamer constructedin accordance with my invention.

Fig. 2 is a diametrical section of the same on the line 2-2 of Fig. 1, with some parts in elevation.

Fig. 3 is a section on the line 3-3 of Fig. 2, with some parts in elevation.

Fig. 4 1s a horizontal section taken in the plane indicated by the line 4-4 of Fig. 2.

Fig. 5 is an enlarged section, partly in the manner n which I prefer to detachably fasten the cutters to the aws.

Fig. 6 is an enlarged inverted perspective of the detent follower for cooperation with the jaws.

Flg. 7 is an enlarged detail perspective showing the type of cutter that is preferably em loyed for soft rock.

imilar numerals of reference designate corresponding parts in all of the views of the drawings.

In furtherance of my invention the body 1 of the underreamer is provided'withlthe following features, viz a bore 2, bifurcations 3, interior longitudinal guides 4 in communication with the bifurcations 3, and recesses 5, Fig. 2.

In addition to the body 1, the underreamer comprises jaws 6, jaw-expanding and cushionin means, and means to yieldingly re-' 1 will be readily understood when it is stated that said means in the preferred specificembodiment of my invention includes a shaft 7 movable in the bifurcations 3 of the body,

anti-friction-rollers 8 loose on said shaft and opposed to cam portions 9 of the jaws 6, rods 10 arranged to move rectilinearly in the guldes 4 of thebody and extending into the body recesses 5 and'springs 11 surrounding the upper portions of said'rods and interposed between nuts or other abutments 12 thereonand opposedportions 13 of the body. The jaw retaining'means includes a detent follower 14 and a spring 15 backing the said detent follower. Thedetent follower 14 is in'the form of'a plate movable bodily in the body bore 2 and having at its'undersidetwo sets of grooves 16, the grooves of one set beveled end 17 of one jaw 6, and the grooves of the of the other jaw. The spring 15 of the jaw retaining means is adapted to counteract or serve as acounterbalance for the springs 11 of the jaw expanding means with a view to contributing to the elastic quality of the underreamer. From this itfollows that incident to the use of the underreamer there is no liability of the jaws dogging in the hole.

In order to cause the jaws 6 to open uniformly I provide in conjunction with each of the jaws a coiled spring 18, sooketed at 19 in the jaw and arranged on a pin 20 carried by the opposed portion of the wall of the bore 2. See- Fig. 3. 1

In Figs. 1, 2, 3 and 5 I illustrate a portable cutter 21 designed more particularly for operation against hard rock, and in Fig. 7 I illustrate a portable cutter 21 designed more particularly for operation against soft rock. The cutters 21 difi'er from the cutters 21 in that the former are toothed as indicated by 22, while the latter are blunt as indicated by 23 in Fig. 7. I designate the cutters as portable inasmuch as they render unnecessary any blacksmith operation in the field, my invention contemplating the removal of a cutter when worn or broken and the replacing of the same with a new cuta ter, any number of cutters being supplied.

other set being arranged to cooperate I wlth the beveled end 17 Specification of Letters Patent. Patented Bag, 27, 31921, Application filed July 9, 1920. Serial 120. 395,043.

projection 27 of the cutter 21 and in which ing positiomand the latter to assist projection 27 is a seat 28 to receive the detent 25. Manifestly when the projection 27 1s slipped endwise into the groove 26, the detent will first be pressed upwardly by the action of the projection 27 against the beveled portion quently will positively and safely secure'the cutter to the jaw. For the ready removal of the cutter 21 I provide the same with a passage 29 through which may be introduced an implement for pressing the detent 25 upwardly against the action of the spring and retaining the detent in its retracted position while the cutter 21 is being withdrawn from ilnderreamer the contact of the jaws or thecutters thereon with the rock will have the effect of expanding the jaws notwithstanding the cobperation of the detent follower 14; with the jaws. The elastic quality ascribed to my novel underreamer is an important characteristic thereof inasmuch as the prevention of the dogging alluded to is calculated to greatly increase the working capacity of the underreamer.

In addition to the practical advantages of my novel underreamer as hereinbefore pointed out it will be noted that the underreamer is simple and inexpensive in construction, is

. well adapted to withstand the usage to which underreamers are ordinarily subjected, and when supplied with fresh cutters as occasion demands isadapted to last in working order for an indefinite period of time. i

Having described my invention, what I claim and desire to secure by Letters-Pat- 1. An underreamer comprising a body, jaws carried thereby and yielding means to cushion and expand the jaws whereby an elastic quality is imparted to the underreamer, in combination with yielding means arranged to act against the jaws counter to the first-named yielding means whereby the elastic. quality of the underreamer is increased.

2.An underreamer comprising a body,

jaws carried thereby'and yielding means to cushion and expand the jaws whereby an elastic quality is imparted to the under reamer', in combination with yielding means of the detent, and when the' seat-28 is coincident with the bore 24 the detent 25 will spring into the seat and consemenses arranged to act against the jaws counter to the first-named yielding means whereby the elastic quality of the underreamer 1S 1n-.

creased, and yielding means to cause the jaws to open uniformly and thereby further increase the elastic quality of' the underreamer. j

3. An underreamer comprising a body, jaws carried thereby and having cam portions, movablemeans carried by the bodyto act against said cam portions, and means to yieldingly hold said movable means against downward movement and'to move said movable means upwardly, in combination with means to exert yielding downward pressure-on the upper ends of the jaws.

.4. An underreamer comprising a body,

jaws carried thereby and having cam portions, movable means carried by the body to act against said cam' portions,.and means to yieldingly hold said movable means against downward movement and to move said'movable means upwardly, in combination with means to exert yielding downward pressure on theupper ends of the jaws, said means including a grooved detent follower, and the upper ends of the jaws being shaped to coeperate with the grooves thereof.

5. An underreamer comprising a body, jaws carried thereby and having cam portions, movable means carried by the body to act a ainst said cam portions, and means to yieldingly hold said movable means against downward movement and to move said movable means upwardly, in combination, with means to exert yielding downward pressure on the upper ends of the jaws, and means to open the jaws uniformly and to cushion the inward movements thereof.

6. An underreamer comprising a body having bifurcations, interior guide ways, and exterior recesses, a shaft movable in the said bifurcations of thebody, rods movable in said guide ways of-the body and connected to said shaft and having abutments disposed in the said recesses of the body, springs surrounding said rods and interthe said bifurcations of the body, rods movable in said guide ways of the body and connected to said shaft and having abutments disposed in the said recesses of the body, springs surrounding. said rods and interposed between said abutments and opposed abutments on the body, jaws carried in the body and having cam portions, anti-friction means mounted on the said shaft and opposed tothe cam portions of the jaws, a deposed between said abutments and. opposed in said guide ways of the body and connectbody and opposed to'the upper ends of the jaws, and a spring backing said detent follower.

8. An underreamer' comprising a body having bifurcations, interior guide ways, and exterior recesses, a shaft movable in the said bifurcations of the body, rods movable ed to said shaft and having abutments disposed in the said recesses of the body,

springs surrounding said rods and interposed between said abutments and opposed abutments on the body, jaws carriedin the body and having cam portions, anti-friction means mounted on the said shaft and 0p posed to the cam portions of the'jaws, a detent follower movable in the bore of the body and opposed to the upper ends of the jaws, a spring backing said detent follower,

and springs in the body and exerting yielding inwar pressure against the jaws.

9. In an underreamer, the combination of a body, ja'wscarried thereby and having beveled upper ends, a detent fol-tower movable in the body andhaving grooves one for each jaw to cooperate with said ends of the jaws, and yieldingmeans-backing the said follower. A I

10. In an underreamer, the combination of a body, jaws carried thereby, and springs one for each jaw interposed between the jaws and the body and arranged to independently exert inward pressure against the upper portions of the jaws.

11. In an underreamer, the combination with a 'aw having a dovetailgroove in its end and also having a bore in communication with said groove, and a spring-pressed beveled detent in said bore, of a portable .cutter having a'dovetail projection toenter said groove, and a seat in sald projection to I receive said detent and also-having a passage through which an instrument may be introduced to retract and hold in retracted position the detent until the cutter is released from'the detent. v p

In testimony whereof I afiix my signature.

THOMAS J. MQCORMICK. 

